WO1991015903A1

WO1991015903A1 - Device for evaluating signal transmission performance of optical communication equipment

Info

Publication number: WO1991015903A1
Application number: PCT/JP1991/000387
Authority: WO
Inventors: Shigenori Torihata
Original assignee: Kabushiki Kaisha Komatsu Seisakusho
Priority date: 1990-03-30
Filing date: 1991-03-26
Publication date: 1991-10-17
Also published as: US5267068A; KR920702113A; EP0480042A1; EP0480042A4; JP2777742B2; JPH03284032A

Abstract

Evaluation of signal transmission performance of optical communication equipment used for optically communicating the signals for controlling general industrial machinery such as press machine. When a current within a predetermined range of magnitude is stepwisely supplied to a light-emitting element (33) of an optical transmission link (3), a frame signal including a current code that represents the magnitude of current fed to the light-emitting element (33) is sent from a transmitter (10) to a receiver (20) via an optical fiber (5). The receiver (20) detects communication errors based on an error check code in the frame signal sent from the transmitter (10). Based on both the content of current code in the frame signal and the result of error detection, the receiver determines the range of magnitude of current for the light-emitting element, within which no error may occur. The transmitter (10) varies the magnitude of current supplied to the light-emitting element (33) and detects the magnitude. Upon receipt of frame signal, the receiver (20) inspects the error check code in the frame signal to detect the communication error, and a range of magnitude of supply current that does not generate communication error is judged from the result of detecting communication error and the result of detecting current supplied to the light-emitting element (33).

Description

Description Device for evaluating signal transmission performance of optical communication equipment

The present invention relates to a signal transmission performance evaluation device of an optical communication device used when optical communication is used for communication in a factory or control in a general industrial machine such as a press machine. Background technology

An optical communication system is used to transmit required data between control devices arranged in various parts of a press machine. The following preprocessing is performed to operate the system.

First, an optical fiber is laid on the site as an optical transmission path between the control devices. A check is performed to determine whether desired light propagation characteristics are obtained for the optical fiber laid next. Then, an optical fiber is connected to the control device to construct an optical communication system.

Such a series of optical fiber laying and pre-processing, such as evaluation of the transmission performance of the optical fiber, are conventionally performed in the following manner. Was.

That is, as shown in Fig. 14, both ends are provided with the required end face treatment, or are provided with connectors. The completed optical fiber 5 itself is laid between the control devices. Then, one end of the optical fiber 5 is connected to the standard light source 6 such as an LED, and the other end of the fiber 5 is connected to the optical power meter. To the data 8. After the connection, the light source 6 is operated, the light generated at the light source 6 is made to enter the optical fiber 5, and the light intensity of the light transmitted through the optical fiber 5 is changed to the optical power. Read with meter 8. At this point, the operator observes the scale of the optical power meter 8 and finds an abnormal attenuation of the optical power with respect to the length of the optical fiber 5. Judgment is made as to whether or not the optical fiber 5 is laid. As a result, if there is no problem, as shown by the white arrows at both ends of the optical fiber 5, the transmission optical link 3 'of the communication device 7 and the reception optical link of the communication device 9 are shown. Reconnect to the connection 4 'to activate the optical communication system. When transmitting the optical fiber 5 to the 'receive links 3' and 4 'in this manner, the power attenuation of the light transmitted through the optical fiber 5 (the Is proportional to the length of the optical fiber 5), and a case for adjusting the optical power supplied to the optical fiber 5 at the transmission link 3 ′ according to There are many. The adjustment of the supplied light power is generally performed by varying the current supplied to the LED which is the light source in the transmitting light link 3 '.

FIG. 15 shows an example of a circuit for adjusting the optical power provided inside the transmission link 3 ′.

As shown in the figure, the distance switching switch 38 is A switch that can be arbitrarily manually switched according to the length of the fiber 5, that is, the communication distance, and the switch 38 has a power supply and an LED 33. The current limiting resistors 35 3, 36, and 37, which have different resistance values respectively, are selectively switched between and to vary the light emission output of the LED 33. On the other hand, the transistor 34 is modulated according to the signal applied to the base terminal, and modulates the light generated by the LED 33 ο and the resistors 36, 3 7 resistance value R

^If the relationship of ^R M ′ ^R H is ^R H < ^R M < ^R L, if the attenuation of the optical path transmitting the optical fiber 5 is large, the resistance 3 7 and medium- and medium-range resistors 36 and small and short-range resistors 35, respectively.

3 O to be selected in 8

As described above, in the conventional technology, the optical fiber 5 is laid at the site, and then the optical fiber 5 is connected to the standard light source 6 and the power meter 8 at the site. Rolling or optical link 3 '

4 There is work to 'slow'. During the installation work and the joining work of the optical fiber 5, both ends of the optical fiber 5 are exposed to the air.o On the other hand, the working environment is If there is oil or dust power inside. Therefore, the propagation characteristics of light are examined at 8 in the optical system, and after measuring the characteristics, when the optical fiber 5 is coupled to the optical links 3 ′ and 4 ′, The upper limit is that the fiber end face is dirty due to the 6s boundary, and the characteristics measured during actual communication cannot be obtained. In addition, the connecting part of the optical amplifier 5 and the optical link 3 ', 4' or the optical fiber 5, the standard light source 6, and the optical power meter 8 Since the transmission characteristics vary with each other, the reading of the optical pa- per meter 8 does not necessarily indicate the transmission characteristics during actual communication as it is.

In addition, the light emitting diode (LED 33) used as a light emitting source in the transmitting optical link 3 ′ generally has high luminous efficiency (forward current VS luminous intensity). Since the light intensity is affected by the ambient temperature and the ambient temperature, it is necessary to take into account the individual variations of the link. The switch 38 must be switched to adjust the optical power, but the characteristics of the individual links cannot be measured by the conventional technology. For that purpose, I had to prepare a separate measuring instrument and check the characteristics of the links 3 'and 4'.

In addition, the sensitivity of the light receiving element of the receiving optical link 4 'also varies. Due to this, even if the light power

As it is, the reading of FIG. 8 does not necessarily indicate the transmission characteristics in actual use.

As described above, the optical fiber 5 after laying in the field has a large variability in the transmission performance when it is coupled to the optical link. The technology has the problem of not being able to accurately evaluate the transmission characteristics of such optical fiber-optical link coupling systems.

Here, the applicant of the present invention has described the We are devising a device that can be laid and connected without being exposed to a dusty and bad environment. In this device, the optical fiber and the optical link are pre-coupled, and the optical fiber integrated with the optical link is laid, and then the optical fiber is cleaned. The coupling work is performed at the electrical connector part of the relatively strong optical link.

The present invention has been made in view of the above circumstances, and the work of connecting the two control devices of the optical signal line to the electrical connector portion of the optical link as preprocessing. It is an object of the present invention to provide a device capable of accurately evaluating the signal transmission performance in actual communication in an optical communication device to be performed. . Uncovering the invention

According to a first aspect of the present invention, a transmitting optical link having a transmitter and a light emitting element is provided on a transmitting side, and a receiving optical link having a receiver and a light receiving element is provided on a receiving side. In the optical communication equipment which is equipped with an optical signal line, the transmitting optical link and the receiving optical link are connected by an optical signal line, A current supply means for supplying a plurality of currents of different magnitudes to the light emitting element; and a current value indicating the magnitude of the current supplied to the previous light emitting element by the current supply means. And a frame signal generating means for transmitting a frame signal including a check code for detecting the occurrence of a communication error. The receiver receives Error detection means for detecting the occurrence of an error based on an error check code in the received frame signal, and a current value code in the received frame signal. And a judging means for judging an appropriate range of a current supplied to the light-emitting element based on the content of the above-mentioned and the detection result of the error detecting means. Adjust the current supplied to the light emitting element.

According to a second aspect of the present invention, in the same optical communication device, the transmitter includes a current value varying unit that varies a magnitude of a current supplied to the light emitting element. Supply current value detecting means for detecting the magnitude of the current supplied to the light emitting element by the current value changing means; and supplying current to the light emitting element by the current value changing means. Signal that sends out a frame signal that includes an error check code to detect the occurrence of a communication error while the supply current of the In addition to the above, the receiver detects the occurrence of an error based on an error check code in the received frame signal. Error detection means, the detection result of the supply current detection means and the detection result of the error detection means Based on the above, the appropriate range of the current supplied to the light emitting element is determined, and the current supplied to the light emitting element is adjusted according to the content of the determination.

That is, according to the configuration of the first invention, a current in a predetermined range is supplied to the light emitting element in the transmitter in a stepwise manner. At the same time, a large amount of current is supplied to the light-emitting element. The current value code is included in the frame signal, and this frame signal is transmitted to the receiver. The receiver detects the occurrence of a communication error between the two transmitters based on the error packet n-mode of the frame signal sent from the transmitter. From the current value code sent from the transmitter and the detection result of the communication error, the range of the magnitude of the supply current to the light-emitting element where no error occurs is generally determined. Adjusting the power supplied to the light-emitting element in accordance with the result of the judgment makes it possible to perform accurate 13 transmission. Swell.

Further, according to the second invention, the magnitude of the current supplied to the light emitting element toward the transmitter can be varied. At this time, the magnitude of the current supplied to the light emitting element is detected. On the other hand, in reception, an error is detected between the two transmitters and the receiver based on the error check sent from the transmitter. The detection result of the magnitude of the current supplied to the light emitting element, the detection result of the error generation and the power, and the magnitude of the current supplied to the light emitting element where no communication error occurs. The range can be determined appropriately. However, if the current supplied to the light-emitting element is adjusted according to the content of this judgment, accurate communication can be achieved. 0 Simple explanation of the drawing Light

FIG. 1 is an evaluation of the signal transmission performance of the optical communication device according to the present invention. FIG. 2 is a circuit diagram illustrating the configuration of a transmission check device in an embodiment of a valuation device, and FIG. 2 is an overall view of an embodiment of a signal transmission performance evaluation device for an optical communication device according to the present invention FIG. 3 is a diagram conceptually illustrating the configuration, FIG. 3 is a circuit diagram illustrating the configuration of the receiving chuck device in the embodiment, and FIG. 4 is a diagram illustrating the output of the D / A conversion circuit shown in FIG. A graph showing the state of change, FIG. 5 is a graph showing the change in the magnitude of the current flowing through the shunt resistor shown in FIG. 1, and FIG. 6 is an LED shown in FIG. 2 is a schematic diagram showing a protocol of a frame signal which is assumed to be transmitted through the optical fiber shown in FIG. 2 through FIG. 7, and FIG. 7 is a diagram showing the flip-flop shown in FIG. FIG. 8 is a diagram partially showing a circuit configuration in which an inverter is used instead of a flip-flop, and FIG. 8 is a transmission check device shown in FIG. FIG. 9 is a circuit diagram showing another example of the circuit configuration, and FIG. 9 illustrates the configuration of a transmission check device in another embodiment of the signal transmission performance evaluation device for an optical communication device according to the present invention. A circuit diagram, FIG. 10 is a circuit diagram illustrating the configuration of a receiving device in another embodiment, and FIG. 11 is a circuit diagram shown in FIG. 2 via an LED shown in FIG. FIG. 12 is a schematic diagram showing a protocol of a frame signal to be transmitted through the optical fiber shown in FIG. 12, and FIG. 12 is another circuit of the transmission chip device shown in FIG. FIG. 13 is a circuit diagram showing a configuration example, FIG. 13 is a circuit diagram showing a modification of the transmission chuck device shown in FIG. 12, and FIG. 14 is a diagram explaining signal transmission performance evaluation of a conventional optical communication device. FIG. 15 is a circuit diagram showing an internal circuit of the transmission link shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

In order to explain the present invention in more detail, the present invention will be described below with reference to the accompanying drawings. Fig. 2 shows the overall configuration of the device of this example.

As shown in the figure, the device of the present embodiment has the actual communication function of the communication device 7 previously shown in FIG. 14 and the transmission check described later. A transmission check device 10 having a function and a reception check similarly having an actual communication function of the communication device 9 and also having a reception check function described later. A transmission line for communication light between the device 20 and the transmission and reception devices 10 and 20, and a transmission optical link (hereinafter referred to as a transmission end) at both ends. The transmission fiber) 3 and the receiving optical link (hereinafter referred to as the reception link) 4 are coupled to each other by the destination fiber 5 or the like. It is composed of Actually, there are many communication devices before the transmission check device 10 and many communication devices after the reception check device 20. In addition, the transmission check device 1 ◦ needs to have a reception check function in relation to the communication device at the preceding stage, and the reception check device 20 also has the reception check device 20 at the latter stage. It is necessary to provide a transmission check function in relation to the communication device. However, for convenience of explanation, these transmission chip apparatus 10 and reception check apparatus 2 are required. The description will be made assuming that communication is performed only between 0 and 0.

The transmission check device 1 ◦ includes an electric connector 1 electrically connected to the electric connector 31 of the transmission link 3. 〇 1 is installed. On the other hand, the reception check device 20 is similarly provided with an electric connector section 201 electrically connected to the electric connector 41 of the reception link 4. that the _c transmits re down click 3, the electrical co Ne click evening portion 3 1 which electric signals are entered, connect one end of the optical full § i Bas 5 in the transmission re down click 3, fixed to Optical fiber connection section 32 is provided. On the other hand, to the receiving link 4, the other end of the optical fiber 5 is connected to the receiving link 4, and an optical fiber connecting section 42 for fixing and an electric signal are output. The electrical connector evening section 41 and the power supply are arranged.

The transmission link 3 has a circuit configuration similar to that of the transmission link 3 'previously shown in FIG. 15, and transmits an electric signal input from the electric connector section 31 to an LED. An electrical / optical converter that converts the optical signal into an optical signal at 33 and transmits it to the optical fiber 5 (this is a circuit shown in the dotted line in FIG. 1 centering on the LED 33). Although not shown, the receiving link 4 converts an optical signal transmitted through the optical fiber 5 into an electric signal, and converts this into an electric connector section 4 1. It is equipped with a photoelectric conversion unit that outputs the light.

Assuming that the optical fiber 5 was laid, the signal transmission performance of the optical fiber 5 including the transmission link 3 and the reception link 4 was evaluated. In other words, the electrical connector section 31 of the transmission link 3 is connected to the electrical connector section 101 of the transmission check device 10 and the electrical connector of the reception link 4. The connector section 41 is the electrical connector section 20 of the reception check device 20. 1 is connected to each.

FIG. 1 shows the transmission check device 10 (shown by a broken line) and the reception link 3 (this is shown) in such a connected state. Are shown as one-point broken lines).

The data as conceptually shown in the following table is stored in the ROM 122 of the transmission check device 10.

Adress evening

0 0 0 0 Start code

Current value code (2 mA) Random signal code Elanar code

0 F F F Stop code

Sky white

1 0 0 0 Start Coat

Current value code (4 mA) Random signal code Error check n —

1 F F F Stop code

Sky white

F 0 0 0 Start code

Current value code (32 mA) Random signal code Error code

F F F F stop code

Sky white That is, in the table, each address 0000 to FFFF is the highest byte C! F F (16) are divided into 16 parts, and the highest byte 0, that is, the address from 0 0 0 to 0 FFF has a start Code, a current value code indicating a current value of 2 mA, a random signal code based on random numbers, a current value code and a random signal code are generated. An error check code and a stop code are sequentially stored as data. In the following, for each address of the highest byte power << 1, 2,…, F, the current value is 4 mA, for every 2 mA, in sequence for the current value code. With a theoretical structure that increases to 8 mA, ... 32 mA, the start code, current value code, ... similar to the highest byte 0 are called. The data of the prototype console is stored and stored.

The clock generating circuit 1226 generates a clock signal having a predetermined period. In synchronization with the generated clock signal, the control signal circuit 125 and the add-on signal are generated. The loss generation circuit 122 sends the stored contents of R0M122 to the parallel / serial conversion circuit (hereinafter referred to as P / S circuit) 123 sequentially. .

In this case, the transmission procedure is performed as follows. For example, the address of the highest-order byte 0 0 0 ◦ After repeating the contents of 0 to 0 FFF ten times in order, and finally sending the highest-order byte The contents of the address 1 100 0 to 1 FFF are repeatedly transmitted 10 times in order, and the same applies to the highest-order pipe and so on. The contents of the addresses of toca 2, 3,… are sequentially transmitted 10 times until the address of the most significant byte; 'F is reached. When the transmission of the contents of the address of the top-level byte card << F has been completed, the transmission of the contents of the address of the top-level byte card << ◦ is started again. And returns a similar transmission.

The address generating circuit 122 outputs an address designating signal for performing such transmission to the ROM 122 and also outputs the address designating signal to the ROM 122. Output to the upper address detection circuit 127. The highest-order address detection circuit 127 detects the end of ROM 122 in response to the input address designation signal. Detects the highest byte 0 to F (consisting of 4 bits) out of FFFF to FFFF and outputs a detection signal indicating the highest byte to the D / A converter circuit 128 . The 0 conversion circuit 128 outputs a signal (analog signal) having a predetermined voltage value according to the input detection signal (digital signal). That is, an analog signal is output so that the output voltage value increases by a predetermined voltage value as the highest-order bita << 0, 1, ..., increases. At this time, the address generation circuit 1221 performs the operation of repeatedly specifying the address of the most significant bytes 0 to F as described above. Therefore, as shown in FIG. 4, the state of the change in the output of the DZA conversion circuit 128 changes from the highest byte 0 to the highest byte F with the passage of time T as shown in FIG. Until this occurs, the phenomenon that the voltage value increases in a step-like manner is repeated.

The output of the DZA conversion circuit 128 is the operational amplifier In addition to the above, the operational amplifier 1229 controls the current of the LED 33 of the transmission link 3 according to the output signal of the D D conversion circuit 128. Hereinafter, the operation performed by the operational amplifier 1229 will be described.

Here, the output current of the operational amplifier 12 9 is limited by the shunt resistance 13 1 and the current limit of the transmission link 3 via the electrical connector sections 101 and 31. Resistor (for short distance) 35 5, LED 33, and transistor 34, and the same output current flows from the shunt resistor 13 1 to the current limiting resistor 13 4 LED 1 3 2, into transistor 1 3 3 o

On the other hand, the output data of the ROM 122 is subjected to the P / S circuit 123 parallel conversion, then the required modulation is performed by the modulation circuit 135 to obtain the D signal. This is input to the D terminal of the type flip-flop 124. The clock signal generated by the clock generation circuit 126 is input to the clock terminal of the flip-flop 124. The signals that are logically inverted with respect to each other are output from the Q and 0 terminals, and the Q output is applied to the transistors 13 and 13. The Q output, as applied to the base terminal, is applied to the base terminal of the transistor 34 of the transmit link 3. In other words, the base input of the transistor 13 and the base input of the transistor 34 are in a logically inverted relationship with each other.

Further, the current limiting resistor 13 4 has the same value as the current limiting resistor 35 of the transmission link 3, and the LED 13 2 has the same value as the current limiting resistor 35. The power of the same quality as the LED 3 3 of the signal link 3 is used. (In general, the variation of the forward voltage is smaller than the variation of the luminous efficiency.) . Similarly, the transistors 13 and 13 of the transmission link 3 and the transmission link 3 are of the same type.

As described above, the base input of the transistor 34 and the base input of the transistor 13 are in a logically inverted relationship with each other. The current flowing through the ton resistance 13 1 becomes a DC current. The voltage drop due to this DC current is amplified by the floating amplifier 130. The amplified output of the floating amplifier 130 is applied to one input terminal of an operational amplifier 129 together with the output of the D / A converter 128. As a result, the output of the operational amplifier 122 changes so as to have the same value as the output of the D / A converter 128. As a result, the current flowing through the shunt resistor 13 1 to the current limiting resistor 35 depends on the output of the DZA converter 128 (FIG. 4). It changes as shown in Fig. 5. In other words, if the current value of the data output from the ROM 122 is less than 2 mA, a current of 2 mA flows through the current limiting resistor 3. As a result, the current value of the data output from the ROM 122, which is output from the ROM 122, will flow through the current limiting resistor 35. .

Therefore, the LED 33 connected to this resistor 35 sequentially emits light according to the current value according to the content of the current value code. As the output voltage changes, the transistor 34 modulates the light in response to the Q output of the flip-flop circuit 124 applied to the base terminal. You In this way, as shown in FIG. 6, one frame is applied to the optical fiber 5 via the LED 33, and the control data is used during the actual communication as shown in FIG. The actual communication code whose contents are the current communication code, that is, the current value code, the random signal code, and the real communication code that is arranged immediately before this actual communication code. The start code indicating the beginning of the code and the code immediately after the above-mentioned actual communication code, and no error occurs when the contents of the actual communication code are connected to the port. Search code and a stop that is located immediately after this error code and indicates the end of one frame. The frame signal composed of the code and the code is transmitted sequentially. Chi I sand, transmit light off A Lee bar 5 in Shi Li A tail current value co one de of the current value 2 m A and to that off-les over beam signal s ₂ force 1 0 times consecutively contents not a or You The light beam at this time has a size corresponding to the current value of 2 mA passing through the LED 33. Later, the current value U over current contents of de 4 m A and to that off-les over beam signal S _lambda force "1 〇 times to atmosphere of the light path was depending on the current value of that in the same way It is transmitted over the wire. Hereinafter, a frame in which the current value of the current value code is increased by 2 mΑ (No. a indicates that the current value of the current value code reaches 32 mA (signal

° 3 2 ⁾ * ^J "Each of them is transmitted continuously for 1 ◦ times and is transmitted again.Then, the signals s 2 to S 32 are transmitted ^{1 Q} times in the same manner. returned . Next, the processing performed by the reception check device 20 will be described with reference to FIG.

As described above, the reception connector 201 of the reception check device 20 shown in the figure has the reception link in the signal transmission performance evaluation of the optical fiber 5 as described above. 4 electrical connector section 41 is connected (not shown).

The opto-electric conversion section of the receiving link section 4 converts the optical signals S ₂ to S ₃₂ transmitted through the optical fiber 5 into electric signals, and converts the converted signals into electric signals. Output from 4 demodulation circuits 2 0 2 receives Li down electric co ne Selector Selector unit of click 4 1, electric co ne Selector Selector unit 2 0 1 required demodulation method a signal S ₂ ~ S ₃₂ that are entered by via , And outputs the demodulated signal to the signal processing circuit 203. The signal processing circuit 2 0 3, you decipher signals s ₂ ~ s _32. In particular, check the error check code, and check whether an error has occurred every frame, that is, the actual communication code is sent correctly. For example, a search is performed using a CRC check method or a vertical / horizontal parity check method. If the error check code indicates that an error has occurred, the error flag is replaced by the error flag count. To the data 204. The signal processing circuit 203 outputs the contents of the current value code to the register 205 and the register 206. The error flag counter 204 is an input error. No error is generated by counting the flag. ぃ Frame power << 5 consecutive times And whether or not it is being transmitted O If, for example, there are 5 consecutive frames at 6 mA, where no error occurs, the error The register 204 gives a command to the register 205, and the register 205 responds to this command and the current value (6 mA) stored at that time is stored. In response to this, the display unit 2-7 displays a signal indicating that the minimum current value is 6 mA, at which no lasing occurs.

After that, when the current value (the content of the current value code) increases, eventually the error flag 2 4 〇 becomes, for example, a current value of 24 mA. Judge that the frame in which no error occurs is not repeated 5 times. Then, the air flag counter 2-4 gives a command to the register 2-6, and the register 2206 stores it in response to this command. A signal indicating the current value (22 mA) immediately before the current value (24 mA) is output to table 208 • S3 o 3¾

In response to this, the display unit 208 displays "No error occurs. Current value is 22 mA."

According to the display of the display units 207 and 208, the LED can transmit accurate data through the optical fiber 5 during the operation. It can be useful to determine the minimum and maximum current values passing through 33. In this case, the optical fiber 5 is used as the only transmitter, and not only the optical fiber 5 is transmitted. ♦ The signal transmission performance of the optical transmission path including the reception links 3 and 4 is indicated by the LED 33. It can be evaluated by the value of flowing current. Therefore, switching and selection of the switch 38 based on this evaluation are performed. In other words, the current value flowing through the LED 33 can be optimally adjusted.

In the embodiment, the current flowing through the LED 33 is set to an initial value of 2 mA, and the current is increased to a final value of 32 mA in steps of 2 mA. Of course, the initial value, the increment of the increase, and the final value of these current values are arbitrary without being limited to these. In addition, the number of repetitions of frame signal transmission is not limited to 10 times, and it is also possible to use the error-flag counter 204 to make a judgment. The threshold value is not limited to five consecutive times, and the number of times can be set arbitrarily.

The division of the address in R0M122 does not have to be 16 divisions. For example, 0 0 0 0 to 0 7 F F, 0 8 0 0 to 0 F F F, 1 0 0 0 to 1 7 F F, F 0 0 to F 7 F F, F 8 0 C! It is also possible to divide the data into 32 as in the case of FFFFF, and the uppermost address detection circuit 127 detects the upper two bytes.

Further, in the embodiment, the frame signal includes a heading force, a start code, a current value code, a random signal code, and an error check code. Force, current value code, random signal code, and error code that consist of protocols such as The order of the codes can be very strong. In addition, the bit length of the random signal code may be arbitrary, and in some cases, the random signal code may be omitted as appropriate. is there . In addition, the error code may be calculated in advance and stored in ROM 12 All or may be generated by an external circuit. .

In addition, it is also possible to carry out an implementation using an infinity 12 4 ′ as shown in FIG. 7 instead of the flip lip 1 24 in FIG. .

In addition, as shown in FIG. 8, the flip-flop 124 shown in FIG. 1 is omitted, and the current limiting resistor 133, the LED 132, the transistor It is also possible to implement the transmission chuck device 11 by using a peak hold circuit 13 6 instead of the impedance switch 13 3.

Further, it is also possible to appropriately omit the modulation circuit 135.

Next, another embodiment of the optical signal line transmission performance evaluation apparatus according to the present invention will be described.

That is, in this embodiment, the entire configuration is basically the same as that shown in FIG. 2 and the transmission check device shown in FIG. Only the configuration of the reception check device 20 shown in FIG. 10 and FIG. 3 is different. Hereinafter, the components having the same functions as those of the previous embodiment will be described with the same reference numerals and the repeated description will be omitted.

The transmission check device 12 corresponding to the transmission check 0 in FIG. 1 is configured as shown in FIG. R0M138 shown in the figure has a start code, a random signal code, and an error code corresponding to each address. Code, stop code power << R

0 Stored in the same manner as M122. The difference from the above R 0 122 is that there is no equivalent to the current value code. The random signal code is determined, for example, by random numbers, and the error check code has been previously generated by this random signal code. Shall do so.

The clock generation circuit 142 generates a clock signal in the same manner as the clock generation circuit 1226, and synchronizes with the generated clock signal to generate a control signal circuit 14. 1 and the address generator 1337 send the stored contents of R0M138 to a parallel / norial converter (hereinafter referred to as P / S circuit) 1339 Let me do it. This transmission operation is repeated until the power of the transmission chuck device 12 is turned off. That is, the address generation circuit 1337 is configured to store the data stored in the ROM 138, the start code, the random signal code, and the error signal. An address designation signal is output to R0M138 so that it is repeatedly sent out to the P / S circuit 139 in the order of the hook code and the stop code. O o

The output data of R0M138 is subjected to parallel Z serial conversion by P / S circuit 139, and then the required modulation is performed by modulation circuit 140. Through the electrical connector sections 101 and 31, the current is applied to the base terminal of the transistor 34 of the transmission link 3.

On the other hand, the voltage variable constant voltage circuit 144 is not shown. The output voltage of this voltage variable constant voltage circuit 14 3 is controlled by an electrical connector section 10. The output voltage of this voltage variable constant voltage circuit 14 3 is manually changed by operating means such as a dial. The current limit resistor (for short distance) 35 of transmission link 3, LED 33, and transistor 34 are applied via 1 and 31. The current limiting resistors 36 and 37 may be applied.

Resistance value of the current limiting resistor 3 5 to here is Ri previously known der, LED 3 3 of the forward voltage V _F your good beauty door run-g is te 3 4 of V cE (Sat) is Ru known der this If the output voltage of the constant voltage circuit 144 is known, the value of the current passing through the LED 33 can be known. The output voltage of the voltage variable constant voltage circuit 144 is measured and displayed by the voltmeter 144. As a result, the operator can easily know the current value passing through the LED 33 by visually reading the display of the voltmeter 144. it can .

As described above, when the output voltage of the voltage variable constant voltage circuit 144 is applied to the current limiting resistor 35, the light emission output of the LED 33 changes according to the magnitude of the applied voltage. At the same time, the transistor 34 modulates light according to the output of the modulation circuit 140 applied to the base terminal. In this way, as shown in FIG. 11, one frame is applied to the optical fiber 5 via the LED 33, and the control data is transmitted during the actual communication. The random signal code where the actual communication code is located and the random signal code that is placed immediately before this random signal code Instructing you And an error sensor arranged immediately after the random signal code to search for the occurrence of an error based on the contents of the random signal code. And a stop code and a force that is placed immediately after this alarm code and indicates the end of one frame. The transmitted frame signal is transmitted repeatedly.

Next, the processing performed by the reception check device 21 corresponding to the reception check device 20 in the previous period will be described with reference to FIG.

In the optical / electrical conversion unit of the reception link 4, the optical signal (FIG. 1) transmitted through the optical fiber 5 is converted into an electric signal. This converted electric signal is output from the electric connector section 41 and is applied to the demodulation circuit 209 via the electric connector section 201.

The demodulation circuit 209 demodulates the input signal by a required demodulation method and outputs the demodulated signal to the signal processing circuit 210. The signal processing circuit 21 ◦ decodes the frame signal shown in FIG. 11. In particular, the error check code is checked to determine whether an error has occurred every frame, that is, the random signal code is correctly transmitted. For example, a search is performed using a CRC check method or a vertical / horizontal parity method. As a result of the inspection of the error code, if it is determined that an error has occurred, the error flag is replaced by the error flag countdown. To the data 211. Error flag countdown 2 1 1 is the input error No error is generated by counting the lag. ぃ It is sequentially determined whether or not the frame signal is transmitted five times in a row. . If it is determined that a frame signal in which no error has occurred has been transmitted five times in a row, the error flag counter 21 1 A signal indicating that no error has occurred is output to the display unit 212. The display 2 12 displays “No error occurred” in response. Conversely, if the frame signal in which the error occurred at least once out of five consecutive times is transmitted, the error flag The counter 21 1 outputs a signal indicating that an error is currently occurring to the display 2 12, and the display 25 indicates “error occurring”. .

Hereinafter, a procedure of signal transmission performance evaluation using the apparatus of the embodiment will be described.

This signal transmission performance evaluation requires at least two operators. On the other hand, the operator A is located on the transmission chuck device 12 side, and transmits the electric connector portion 101 of the transmission device 12 to the electric connector portion of the transmission link 3. 3 Connect to 1 and turn on the power of the transmission tick device 12 to operate it as described above.

The other operator B is located on the receiving chuck device 21 side, and similarly, the electrical connectors of the receiving device 21 and the receiving link 4 are connected to each other, and the receiving chip is connected. The check device 21 is operated.

Next, the operator A is a voltage variable constant voltage circuit. Operate this dial to gradually increase the output voltage of the circuit 144 from the lowest voltage.

While the output voltage of the voltage variable constant voltage circuit 144 is low, the current value passing through the LED 33 is correspondingly low, and the power of the LED 33 is low. The number supplied to 5 is getting smaller. For this reason, the frame signal is not transmitted accurately and accurately, and the display 21 of the reception check device 21 displays "error occurring". As the output voltage of the voltage variable constant voltage circuit 144 increases, the supply current to the LED 33 increases, and the power supplied to the optical fiber 5 is reduced. As a result, the power to be displayed increases, and at a predetermined output voltage value, the display 25 starts to display "no error".

At the time of this display, the operator B sends a signal to the operator A indicating that "no error has occurred" by raising the hand or the like. In response to this signal, the operator A reads the voltage value of the variable voltage constant voltage circuit 144 displayed on the voltmeter 144 and converts it to a current value. As described above, it is possible to know the minimum current value at which no error occurs, similarly to the above-described embodiment. If the distance between the operators AB is large or if the visibility between the two is not good, for example, transmission of information from a transceiver, etc. Just use the means.

Then, as operator A continues to raise the output voltage of voltage variable constant voltage circuit 144, it will take a while for a while. Although "No error has occurred" is displayed on the indicator 2 12, the display 2 12 will soon show "Error occurring" at the specified output voltage value. . At this point, the operator B sends a signal to the operator A, and the operator A reads the voltage value of the voltmeter 144 at this time and converts it into a current value. You Therefore, it is possible to know the maximum current value at which no error occurs.

Thus, in this embodiment, the operator transmits the exact data through the optical fin 5 through the display of the voltmeter 144. It can determine the minimum and maximum current values that can pass through the LED 33. At this time, the transmission of light fiber was not limited to optical fiber alone.

• The signal transmission performance of the optical transmission line including the receiving links 3 and 4 can be evaluated by the current value flowing through the LED 33.

Based on this evaluation, switching and selection of the switch 38, that is, adjustment of the current value flowing through the LED 33 can be optimally performed based on the evaluation.

In the embodiment, the threshold value of the judgment performed by the error flag counter 211 is set to five consecutive times. However, the present invention is not limited to this. The number of times is arbitrary.

Further, in the embodiment, the frame signal is output from the head signal, the random signal code, the random signal code, the error check code, and the stop signal. The order of the random signal code and the error check code is as follows: Even if you try to come first Good

The error check code may be calculated in advance and stored in R0M138, or may be generated by an external circuit. O

Further, an embodiment in which the modulation circuit 140 shown in FIG. 9 is omitted as appropriate is also possible. When this modulation circuit 140 is omitted

A '

In this case, the demodulation circuit 209 shown in FIG. 10 can be omitted.

Next, Fig. 12 shows the current measurement error due to the current limit resistor 35, the forward voltage V of the LED 3 and the VCE (Sat) of the transistor 34, and Fig. 9 shows the measurement error. The configuration of a transmission check device 13 that can be significantly reduced more than the above is shown.

That is, as shown in the figure, the output of the modulation circuit 140 is not input to the D terminal of the D-type flip-flop 144, and the flip-flop is not connected. The clock signal generated by the clock generation circuit 142 is input to the clock terminal of the clock 15. The flip-flop outputs the signals that are logically inverted from each other from the Q and Q terminals, and the Q output is the output of the transistor 1449. In addition to being applied to the base terminal, the Q output is applied to the base terminal of the transistor 34 of the transmit link 3. That is, the base input of the transistor 1449 and the base human power of the transistor 34 do not have a logical inversion relationship with each other.

In addition, the resistance value of the current limiting resistor 147 is The resistance is the same as the resistance of the anti-35, and the LED 148 is the same as the LED 33. Similarly, transistor 1449 and transistor 34 are of the same type.

The output voltage of the voltage variable constant voltage circuit 144 is applied to a shunt resistor 150, and furthermore, a current limiting resistor 144, an LED 144, and a transistor 144 are provided. Is applied to the transmission connector 3 via the electrical connector sections 101 and 31 to the current limiting resistor 35, the LED 33, and the transistor 34 of the transmission link 3. Applied.

As described above, the base input of transistor 34 and the base input of transistor 149 have a logically inverted relationship with each other. Flows into the shunt resistor 150

¾ i) ¾ (3 · DC current. The pressure drop due to the four DC currents is amplified by the floating amplifier 146, and the amplified voltage is measured by the voltmeter 14. Measured and displayed at 4. Therefore, the operator passes the LED 33 by visually observing the display of the voltmeter 144. It is easy to know the current value. Thus, in this embodiment, the output voltage of the voltage variable constant voltage circuit 144 is not measured as it is. Since the voltage drop due to the direct current flowing through the shunt resistor 150 is measured, the above-mentioned variation in the forward voltage of the LED 33 is checked. As a result, the measurement error of the turbulence value is reduced, and more accurate measurement can be performed. In addition, as shown in FIG. 13, the flow chart shown in FIG. Flip-flop 145, current limiting resistor. 147, LED 148, transistor 149 are omitted and floating amplifier 145 is omitted. A peak hold circuit 15 1 is added after 6 and the peak voltage value detected by the peak hold circuit 15 1 is measured by a voltmeter 14 4. It is also possible to carry out such measures.

In the embodiment, at least two operators are arranged, and one of the operators displays the voltmeter 144 with respect to the other operator. Although the reading instruction is given, it is also possible to carry out this automatically. That is, for example, the transmission check device and the reception check device are connected to each other by a required signal line or radio, and these signal lines are connected via these signal lines. The contents of the display unit 212, that is, "No error has occurred" and "Error has occurred" are displayed from the receiving device to the transmitting device. In addition to the sequential transmission, the transmission check device may automatically output the transmitted sequential contents of the display unit 2 12 automatically. .

In the embodiments, an optical fiber is used as a transmission medium of an optical signal. However, the present invention is limited to an optical fiber as a matter of course. An optical signal line that can transmit an optical signal without being transmitted may be used.

Further, in the embodiment, an LED is used as a device for converting an electric signal into an optical signal, and the present invention is not limited to the LED. Without being limited, electricity Any light-emitting element that can convert a signal into an optical signal is optional.

Further, in the embodiment, a force for displaying whether or not an error has occurred on the receiver side on a display device, and a determination result of whether or not an error has occurred are shown. The output means is optional, and may be, for example, printed.

As described above, according to the embodiment, the following effects can be obtained.

First, when evaluating the signal transmission performance of an optical communication device, there is no need to change the connection by exposing the end face of the optical signal. The ability to perform accurate evaluations without any difference in transmission performance

Further, in the embodiment, the optical signal is input and the signal line from which the optical signal is output is not evaluated only. Instead, the ^ £ ia signal is input and the signal is output. Evaluate the optical transmission path, including the transmission link that converts it to an optical signal and transmits it to the signal line, and the reception link that converts the transmitted optical signal into ¾ \ i's and outputs it. In this way, it is possible to make an evaluation that takes into account the link latency, and there is no need to worry about link latency. As a result, the efficiency of the evaluation work is dramatically improved. In addition, there is a variation in the luminous efficiency of light-emitting elements such as LEDs in the transmission link, but this need not be considered separately.

In the embodiment, the current supply during actual communication is performed. In order to evaluate the performance of the optical signal line by measuring the amount of current supplied to the light-emitting element such as the LED in the transmission link to be adjusted. Therefore, it is possible to obtain optimal information in accordance with the transmission strength adjustment in actual communication, and to accurately adjust the transmission strength. In addition, there is an advantage that the noise margin can be evaluated based on the measured current supply amount.

In the embodiment, as in the actual communication, a serial frame signal is transmitted to the optical signal line for evaluation, so that the optical signal line is used as the optical signal line. In particular, it will be possible to simultaneously evaluate the performance degradation due to dispersion and the like that occurs when an optical fiber is used.

In addition, since the evaluation was made under the actual communication conditions, it was possible to inspect the error check code, and thus the electromagnetic noise was evaluated. It is possible to grasp the error occurrence rate under the noise environment. INDUSTRIAL APPLICABILITY As described above, the present invention can be applied to the case where the signal transmission performance of an optical communication device is evaluated.

Claims

The scope of the claims

(1) The transmitting side is equipped with a transmitting optical link equipped with a transmitter and a light-emitting element, and the receiving side is equipped with a receiving optical link equipped with a receiver and a light-receiving element. In an optical communication device in which the link and the optical link for receiving light are connected by an optical signal line,

Early transmitter

Current supply means for supplying a plurality of currents of different magnitudes to the light emitting element;

A current value code indicating the magnitude of the current supplied to the light emitting element by the current supply means and an error check code for detecting occurrence of a communication error. Frame signal generating means for transmitting a frame signal including

And the receiver comprises:

Error detection means for detecting the occurrence of an error based on an error check code in the received frame signal, and a current value in the received frame signal. Determining means for determining an appropriate range of the current supplied to the light-emitting element based on the content of the code and the detection result of the error detecting means; and responding to the determination result of the determining means. A signal transmission performance evaluation device for an optical communication device, wherein the current supplied to the light emitting element is adjusted in the same manner.

(2) The transmitting side is equipped with a transmitting optical link having a transmitter and a light emitting element, and the receiving side is provided with a receiver and a light receiving element. In an optical communication device provided with a communication optical link, the transmission optical link and the reception optical link are connected by an optical signal line.

The transmitter is

Current value varying means for varying the magnitude of the current supplied to the light emitting element;

Supply current value detection means for detecting the magnitude of the current supplied to the light emitting element by the current value variable means, and supply current to the light emitting element by the current value variable means Frame signal generating means for transmitting a frame signal including an error check code for detecting the occurrence of a communication error while the signal is being varied.

And the receiver comprises:

Error detection means for detecting the occurrence of an error based on an error check code in a received frame signal.

Determining an appropriate range of the supply current to the light emitting element based on the detection result of the supply current detection means and the detection result of the error detection means, and according to the determination content, A signal transmission performance evaluation device for an optical communication device that adjusts the current supplied to an element.